Wall-associated kinase 1 (WAK1) is crosslinked in endomembranes, and transport to the cell surface requires correct cell-wall synthesis
Wall-associated kinase 1 (WAK1) is crosslinked in endomembranes, and transport to the cell surface requires correct cell-wall synthesis
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DOI：
10.1242/jcs.02968
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发表时间：
2006-06-01
影响因子：
4
通讯作者：
Byers, Nicole
中科院分区：
文献类型：
--
作者：
Kohorn, Bruce D.;Kobayashi, Masaru;Byers, Nicole
拟南芥壁相关激酶 (WAK) 通过胞外结构域与果胶结合，并且还包含胞质蛋白激酶结构域。 WAK 是细胞伸长和调节糖代谢所必需的。这项工作表明，在叶子原生质体中，WAK1-GFP 融合蛋白在含有果胶的细胞质区室中积累。 WAK 区室包含高尔基体（果胶合成部位）的标记。 WAK1-GFP 向细胞表面的迁移比与细胞壁不相关的细胞表面受体慢得多，受到一种或多种可能包括果胶的未识别分子上岩藻糖侧链存在的影响，并且依赖于质膜上的纤维素合成。 WAK 在出现在细胞表面之前，在细胞质区室中交联成去污剂不溶性复合物，并且这与岩藻糖修饰或纤维素合成无关。因此，WAK 的组装和交联可能在细胞质区室中的早期阶段开始，而不是在细胞壁本身中，并且与表面纤维素的合成相协调。
The Arabidopsis thaliana wall- associated kinases ( WAKs) bind to pectin with an extracellular domain and also contain a cytoplasmic protein kinase domain. WAKs are required for cell elongation and modulate sugar metabolism. This work shows that in leaf protoplasts a WAK1- GFP fusion protein accumulates in a cytoplasmic compartment that contains pectin. The WAK compartment contains markers for the Golgi, the site of pectin synthesis. The migration of WAK1- GFP to the cell surface is far slower than that of a cell surface receptor not associated with the cell wall, is influenced by the presence of fucose side chains on one or more unidentified molecules that might include pectin, and is dependent upon cellulose synthesis on the plasma membrane. WAK is crosslinked into a detergent- insoluble complex within the cytoplasmic compartment before it appears on the cell surface, and this is independent of fucose modification or cellulose synthesis. Thus, the assembly and crosslinking of WAKs may begin at an early stage within a cytoplasmic compartment rather than in the cell wall itself, and is coordinated with synthesis of surface cellulose.